Struct Skein512 

pub struct Skein512 {
    pub n_blocks: usize,
    pub message: Vec<[Wire; 8]>,
    pub digest: [Wire; 8],
}

Skein512 circuit that processes a fixed number of 64-byte message blocks

This circuit implements the full Skein-512 hash function for fixed-length inputs, following the reference implementation. Unlike variable-length hash circuits, this expects exactly n_blocks of 64 bytes each as input.

Circuit Structure

1. Configuration Block: Process fixed config block to establish initial chaining value
2. Message Blocks: Process each of the n_blocks message blocks in sequence
3. Output Block: Generate final 512-bit digest

Each stage uses UBI (Unique Block Iteration) compression with appropriate tweak values.

Arguments

• n_blocks - Number of 64-byte message blocks this circuit will process
• message - Vector of message block wires, each containing 8 × 64-bit words
• digest - Array of 8 wires representing the 512-bit output digest

Fields

n_blocks: usize

Number of 64-byte blocks this circuit processes

message: Vec<[Wire; 8]>

Input message as blocks of 8 × 64-bit words each

digest: [Wire; 8]

Expected 512-bit digest as 8 × 64-bit words

Implementations

impl Skein512

pub fn new(builder: &CircuitBuilder, n_blocks: usize) -> Self

pub fn populate_message( &self, w: &mut WitnessFiller<'_>, message_blocks: &[[u8; 64]], )

Populate the message wires with input message blocks

pub fn populate_digest( &self, w: &mut WitnessFiller<'_>, expected_digest: [u8; 64], )

Populate the digest wire with expected hash output

pub const fn digest_wires(&self) -> [Wire; 8]

Get the digest wires

pub fn message_wires(&self) -> &[[Wire; 8]]

Get the message block wires